Radiofrequency transformer



l July 6, 1926.

1,591,507 N. E. BORCH RADIOFREQUENCY TRANSFORMER Filed July 15. 1922 whhygrllw'- INVENTOR JY/LS E. BURC/l Patented l.l'ulyy26,1926. i I

UNITEDI STATES PATEN'r` OFFICE.

NILS E. BORCH, OF BERKELEY, CALIIOBNIA.

mmornnounncy Tmsronmnn.

Application mea my' 15, 1.922. sei-m1 No. 575,308.

My invention is an improvement in radio for the inductive circuits set up bythe coils 3Q frequency transformers. v 2 and 3. f i v The objectof my invent-ion is to provide a A sleeve 7- su'rrounds the material 6, and transformer which is simple in construction, has .heads 8. and 9.'` Bindin posts 10 are '6 and which has a core which also serves as secured to the head 8 an posts 11 are a screen.- secured to the head 9. iPrimary leads 4 are u Another object of my invention'is to prof-Seemed to theposts 10 and secondary leads vide a transformer which is inexpensive to 5 are secured to the posts 11. l i

Amanufacture, and eilicient ino eration. My transformer may be\used in any of 10 Referring to the drawing'wiiich forms a the wellknownradio receiving circuits a8 part of thisspeciicationis illustrated in Fig. 3. y e primary ,coil l Fig. ll lis a Eerspective view of my trans- 2 is placed in series with the grid of an 'v former with t e casing removed'. audiotube 12 and a battery 13, and the sec- Fig. 2 is a transverse sectional view of my ondary coil 3 is placed in series with the re- 15 transformer. sistancecoil ofen audio tube 1 4 and with a 'Finn 3 is the wiringl diagram of a radiol variometer 15. A battery l16 is wiredl in 4I circuit embodying my invention. series with the incandescent filaments of Referring'more particularly to the drawtubes 12 and 14 and the aerial (not shown) f is attached to the resistance coil of the tube 1n A20 i'he numeral 1 indicates'a. sleeve, upon 12 and to one lead of the secondary coil 3.

which is wound a primary coil 2 and a sec- Having described my invention,Iclaim:- I0 ondary coil 3. Leads 4 extend from the A radio 4frequency .transformer comprisprimary coil 2, and leads 5 extend from thev ing a sleeve, primary and secondary coils secondary coil 3. wound on 'said-sleeve, and a. conductive ma- A material 6 consisting-of laster of Paris". terial consisting of -plaster of Paris and steel and fine steel filings mixedp therein, com- "filings, surrounding said sleeve u pletel covers the sleevel and also iills the In testimony whereof I ailix my signature.

bore t ereof, thus formin 'a core. The mal terial 6 isa conductor ang serves as a screen NILS E.- BOBCH. 

